Coupling apparatus for watercraft

ABSTRACT

An apparatus for coupling a pushed vessel with a pushing vessel by connecting to the stern of the pushed vessel a universal thrust coupling providing for three degrees of freedom of movement between the pushed vessel and an elongated compression connecting member connected at one end thereof to the thrust coupling and at the other end thereof to the mid-ship portion of the pushing vessel and being pivotably movable with respect to the pushing vessel about an athwartships axis of the latter, whereby said pushing and said pushed vessels are linked together for joint movement while being free to heave as well as roll, yaw and pitch relatively to one another.

White Melee nte v Dereelrtor [4 1 Mari. 2% 11%? 2 [54] C(NUPLHNG APPARATUS F OREIGN PATENIQR ABR CQT KQPQ M WATERQRAW 1,247,894 3311967 Germany ..1 14/235 n [72] inventor: Robert E. Derecktor, Parsonage Point,

Rye, 105 30 Primary Examiner-Trygve M. Blur It H St b 22 Filed: Feb. 17, 1970 A my cm W [21] Appl. No.: 111,978 [57] ABSTRACT An apparatus for coupling a pushed vessel with is pushing ves- [52] US. Cl. .lM/ZBS R sel by connecting to the stern of the pushed vessel a universal [51] Int. Cl "M62": 21/00 thrust cou ling providing for three degrees of freedom of [58] Field Of Search ..1 14/235 R, 235 A, 230 movement between the pushed vessel and an elongated com.

pression connecting member connected at one end thereof to v [56] References Cited the thrust coupling and at the other end thereof to the mid- UNITED STATES PATENTS ship portion of the pushing vessel and being pivotably movable i with respect to the pushing vessel about an athwartslups axis 3,353,512 11/ 1967 Mathews et al. ..1 14/235 R f the latter, whereby said pushing and said pushed vessels are 3,461,829 8/1969- .Mosvold ..ll4/235R v linked together for joint movement while being free to heave as well as roll, yaw and pitch relatively to one another.

22 flaims, 5 Drawing Fignre COUPLING APPARATUS FOR WATERCRAFT This invention relates to the field of marine conveyances. Particularly, this invention relates to an apparatus for connecting a first water craft such as a tugboat in a pushing relationship with a second water craft such as a barge for the purpose of having the tugboat push the barge.

There are advantages to having a tugboat push a barge as contrasted with a tugboat pulling a barge. With the tug pushing rather than towing the barge, there is, of course, no resistance of a tow line dragging in the water since there is no tow line. Also, the tugboat can maintain closer surveillance over the barge because of the closer connection between tugboat and barge. in rough water the tugboat is afforded protection from waves since the barge proceeds ahead of the tugboat and, as a result, the pushing tugboat may maintain speed for a longer period of time in rough water conditions than a tugboat towing a barge. Further, there is no danger of losing a barge such as might result from a breaking of the flexible tow line. When the tow is ahead of the tugboat and connected to it, the tow is much more controllable including the ability of the tugboat to stop the tow quickly and even reverse the movement of the tow if necessary.

Moreover, a vessel towed aft of the tugboat may, particularly if the line is long, encounter forces setting up a yawing oscillation. Also, a tow line connecting the tow to the tugboat,

particularly if the latter is long, offers substantial resistance to forward movement. Higher speeds of the tugboat and tow are therefore possible where the tow is ahead of the tugboat. Moreover, location of the tow ahead of the tugboat removes it from the wash of the propellers which would otherwise produce additional resistance to movement of the tow. The operating efficiency of the tow and tugboat combination where the tow is ahead of the tugboat is thus greater and the operating cost is lower.

For these reasons it is very desirable for the tow to be located ahead of the tugboat. But in such relationship it is essential that the coupling between the tugboat and the tow be such as to enable the tugboat to maneuver the combination effectively. In the past the connection between the tugboat and the tow in such combinations has not afforded sufficient ability for relative movement of the tugboat and the tow, except for navigation on inland and completely protected water. For operation in rough seas, however, the known systems were not satisfactory. Consequently it has been the usual practice heretofore, in tugboat and tow combinations navigating in the open sea or in unprotected coastal waters, for the tow to be located aft of the tugboat and connected to it by a hawser.

Both the tow and the tugboat in a sea are subjected independently to the forces of the wind, the waves and perhaps currents tending to make them pitch, heave, roll and yaw independently. ln pitching, a vessel alternately rotates in opposite direction about its lateral axis. In rolling, a vessel rotates generally about its longitudinal axis. In heaving, the entire vessel alternately plunges and rises more or less without pitching and rolling. In yawing, the bow of a vessel will swing from its course to one side or the other.

According to one known system the pushed vessel is provided with a notched stern to allow the pushing vessel to enter its bow into the notch for pushing. In this system the bow of the pushing vessel rides up and down in the notch due to relative pitching between the vessels thereby lessening the control between the vessels and producing excessive wear and potentially hazardous relative motions, particularly in rough waters. In another known system, the pushing vessels bow is butted against a flat fender or plate located at the stern of the pushed vessel and the bow of the pushing vessel is permitted to ride up and down against this plate, again resulting in potentially hazardous motions.

While apparatus is known for coupling together a tugboat and a barge with the tugboat aft of the barge, such known apparatus also does not permit satisfactory maneuverability of the barge and tugboat combination, particularly in rough seas. Substantial stresses and strains are encountered, especially in rough seas, as a result of the natural tendency of spaced apart vessels to roll and yaw relatively to one another due to the uncontrollable and nonuniform action of the waves, wind and currents acting independently on each of the pair of vessels.

One known apparatus for directly coupling a pushing tug to a pushed barge is that described in U.S. Pat. No. 3,257,986 which, while permitting relative pitch and heave movements between the coupled vessels actually restrains relative yaw and rolling movements. Since relative yaw is prevented, the vessels must be steered as a unit, thus even further greatly reducing maneuverability.

In still another known system, described in US. Pat. No. 3,461,829, the bow of the pushing vessel is connected directly, via a thrust coupling, to the stern of the pushed vessel with the result that while relative yaw and roll movements are permitted between the vessels, no relative vertical, i.e., heaving movement between the bow of the pushing vessel and the stern of the pushed vessel is possible while the vessels are underway, thus restraining relative movement of the bow of the pushing vessel with respect to the stern of the pushed vessel at least with respect to one degree of freedom necessary for underway condition in rough seas, namely, relative vertical movement.

Furthermore, because of the direct connection between the stern of one and the bow of the other, the vessels cannot pitch entirely freely relative to one another. The pitching of one must necessarily affect the motion of the other since when the bow of the pushing vessel rises it will exert an upwardly directed force on the stern of the pushed vessel while when the bow of the pushing vessel plunges it will exert a downwardly directed force on the stern of the pushed vessel and vice versa.

The principal object of the present invention is, therefore, to provide a simplified apparatus for coupling a tow to and forward of a tugboat in such a manner as to permit not only relative rolling and yaw or relative pitching and heaving between the two craft, but to permit all or any combination of these relative movements likely to be encountered by such craft in rough waters.

More specifically, it is an object of the present invention to provide a connection between a tow and a tugboat which will substantially restrain relative longitudinal displacement of the tug and tow or of two tows coupled together while enabling such vessels to execute freely relative pitch, yaw, roll and heave movements.

A further object is to provide a coupling for connecting a tow and a tugboat or two tows which is simple, compact and sufficiently rugged to withstand the forces acting upon the vessels independently.

Another object is to provide such a coupling which can be disconnected quickly and easily so that a single pusher-tug can be disconnected from a first tow and thereafter easily coupled in pushing relation to a second tow.

Advantageously the apparatus for connecting the two vessels comprises an elongated compression connecting member pivotably supported at one end thereof approximately amidships of the pushing vessels for pivotal movement about an athwartships axis thereof and connected at its opposite end to a universal thrust coupling located forward of the bow of the pushing vessel and connected, via a suitable support, to the stern of the pushed vessel. The elongated connecting member preferably straddles the bow of the pushing vessel or tugboat with sufficient clearance therebetween to permit the bow of the tug to undergo substantial pitching movement relative to the connecting member in the clearance space provided therein.

It will be appreciated that the universal thrust coupling may be formed so that it has a series of three pinned joints in which rotatable motion is provided about X, Y and Z axes thus providing three degrees of motion, each about a separate axis, with all the latter axes being in a confined area. Meanwhile, the elongated connecting member is itself pivotable with respect to the pushing vessel about an athwartships axis amidships thereof. Accordingly, said pushing vessel and said pushed vessel will be free to heave, i.e., to rise and fall as well as roll, pitch and yaw, relatively to one another.

The foregoing objects and advantages of the invention will be more fully understood when read in the light of the accompanying description and drawings representing preferred embodiments, which are given only by way of illustration of the inventive concepts herein, and not as limitations thereof, and in which:

FIG. 1 is a plan view of the stern portion of a square stern barge tow and a pointed-bow tugboat combination with the tow forward of the tugboat and connected to it by a coupling according to the present invention, showing in full lines a tugboat coupled in line" to the barge, and showing in broken lines the tugboat in varying angular positions with respect to the barge, to effect forward motion and steering;

FIG. 2 is a starboard side view in elevation showing the midship portion ofa tugboat coupled, according to the present invention, to the stern portion of a barge, with both vessels in generally longitudinal alignment in relatively smooth water;

FIG. 3 is a starboard side view in elevation showing the vessels coupled as in FIG. 2 and pitched relatively to one another, as in rougher water;

FIG. 8 is a vertical transverse section through a tugboat amidships thereof and illustrating relative rolling motion of a tugboat and barge connected with the apparatus of the present invention; and

FIG. is an exploded magnified view, in perspective, of portions of the universal thrust coupling according to the present invention.

Referring to the drawings and first to FIG. 1, a pushing vessel or tugboat 10 is shown releasably coupled at its mid section to the stern 41 of a material-carrying barge 40. The coupling apparatus according to the present invention preferably comprises a pair of support members 12 and 12', located on opposite sides of the tugboat preferably approximately amidships and bolted or otherwise suitably secured to the sides of the tugboat 10. Each of the support members 12 and 12 is provided with a pivot means 12A and 128, respectively, having a common pivot axis, namely, athwartships axis A preferably located at a higher elevation than, but in the region of the center of buoyancy B" of the tugboat. The pivot means 12A and 128, may include pivot pins 13A and 138, respectively, coaxial with axis A."

While in the preferred embodiment the athwartships axis A is in substantially vertical alignment with the center of buoyancy B of the tugboat, such relationship is not essential to the present invention and variations therefrom along the ship's longitudinal axis of distances of up to plus or minus 25 percent of the longitudinal length of the tugboat are intended to be included within the scope of the present invention. Thus, the mid 50 percent of the tugboat, as measured longitudinally thereof, centered about the center buoyancy B, is intended to be included in the use of the term herein ofmidship portion or amidship" of the tug.

Pivotably supported on the support means 12, 12' is a generally U-shaped, elongated, compression connecting member 21 (FIG. 1) which has a broad forward end portion 21A and a pair ofleg portions 22A and 22B stradding the bow portion 14 of tug 10. The leg portions 22A and 22B extend aft of portion 21A and are pivotably supported in the region of their free ends, on the pivot means 12A and 12B, respectively. Connecting member 21 may have its forward portion 21A in the form of a truss having a plurality of strengthening members such as chords 23A, 23B, 23C, etc. The innermost of these members, namely, chords 23A and 23B, and the legforming members 22A and 22B, are sufficiently spaced from adjacent portions of the bow 14 of the tug, straddled thereby, to provide sufficient clearance for relative swinging movement of the member 21 about the axis A into and even beyond the position illustrated in FIG. 3.

Rigidly bolted or otherwise suitably secured to the stern 41 of the barge, i.e., the pushed vessel 40, is a second support means 42 in the form of a truss having an upper portion 42A and a vertically spaced lower portion 428, each of which extends aft of the stern 41 of the barge. Thus portions 42A and 428 may each be, as seen in FIG. 1, in the form ofa V-shaped truss, 44A, 45A and 44B, 4513, respectively, connected at its free ends to horizontally spaced portions of the stern of the barge and having central longitudinally extending truss portions 46A, 46B, respectively, connecting the apexes of the corresponding truss portion with the midportion of the stern of the barge. Viewed in elevation, the upper and lower portions 42A and 42B of the second support means 42, preferably taper away from each other (FIG. 2) aft of the stern and then taper toward each other so that at a predetermined distance aft of the barge, i.e., a distance which is preferably slightly greater than one-half the width of connecting member 21, said upper and lower portions are closest to one another, namely at their apexes.

Preferably also, the upper and lower truss members of said second support means are formed at their apexes into substantially parallel, horizontal, planar portions 43A and 438, respectively, formed with coaxial vertically spaced openings 39A and 398, respectively.

Coupling the forward end 21A of the elongated compression connecting member 21, with the second support means 42, rigidly mounted on the stern of the barge, is a thrust coupling means 30 (FIG. 1).

Coupling means 30 has three associated separate axes of rotation, each axis of rotation providing one of the movements of roll, pitch and yaw. This coupling means comprises three major articulated portions or units 31, 32 and 33 (FIG. 5). Articulated unit 33 is located at the forward end of and integral with the elongated connecting member 21. The units 31, 32 and 33 are operatively pivoted together. Units 31 and 32 are connected by pivot pin 32B, and units 32 and 33 are connected by pivot pin means 33A. Furthermore, unit 31 is pivotably connected to portions 43A and 43B of the truss 42 by a pair of coaxial pivot pins 31A and 31B which extend through the openings 39A and 398, respectively.

Unit 33 includes a pair of spaced preferably parallel arms 34A and 34B extending at right angles to and integral with the forward end 34 of member 21. Arms 34A and 34B are preferably formed with forked end portions 34A and 34B defining a pair of coaxial channels 35 opening in forward direction and adapted to respectively receive therein opposite end portions of the pin means 33A.

Unit 32 includes a partially cylindrical portion 32A of a length adapted to fit between the spaced arms 34A and 34B of the unit 33 and defining therein a hole 36 through which the pin 33A extends and in which said pin is securely held. A pair of arms 50 and 51 are swivably connected to opposite sides of the fixed arms 34A and 34B, respectively, for swinging movement about pivot members 50A and 51A, respectively, in directions normal to the axis of the pivot means 33A. The arms 50 and 51 are provided with forked end portions 508 and 51B respectively forming channels 52 opening in a direction substantially perpendicular to the direction of opening of the channels 35 and also adapted to receive therein spaced portions respectively of the pivot pin 33A. The fixed arms 34A and 34B, together with the movable arms 50 and 51 form a releasable locking means for releasably holding therebetween, when said channels are in registry, said spaced portions respectively of the pivot pin 33A, while permitting the latter to freely pivot in said aligned channels. Thus, the units 32 and 33 are articulately connected for rotation about normally horizontal axis of pitch Z when the tongue 32A is inserted in the groove formed between fixed arms 34A and 34B and the channels 35 and 52 are brought into registry with each other and with pin 33A. Unit 32 also includes a cylindrical extension 328 located at right angles to, and integral with, portion 32A.

Unit 31 is provided with a cylindrical bore 37, extending therethrough and having an axis X," and adapted to receive therein the extension 32B of unit 32 for articulately connecting units 31 and 32 for relative rotation about the normally horizontal axis of roll X." Unit 31 further defines a pair of additional coaxial openings 38 and 38 along a normally vertical axis of yaw Y" normal to and intersecting the axis X."

Openings 38 and 38 are adapted to receive the pins 31A and 313, respectively. The flanges 43A and 43B of truss 42 are spaced apart along said normally vertical axis Y" a distance sufficient to receive therebetween the unit 31 with the holes 33 and 38 thereof in registry with the holes 39A and 3913, respectively.

The pins 31A, 318 may each be formed with a head 31A, 3113' at one end and a threaded portion at the opposite end for engagement with corresponding threads, provided in openings 38A and 38 of unit 31. Similarly, the pins 50A and 51A may be provided with a head portion at one end and a threaded portion at the opposite end thereof so as to be retained in position on member 21 pivotably supporting thereon the arms 50 and 51 (FIG. 5). Also, the cylindrical extension 328 of unit 32 may be provided at its free end with a threaded portion for receiving a retaining nut 323' for making secure the pivotable connection between units 31 and 32.

It will be readily understood that units 32 and 33 form, together'with the pin 33A, a pivotable tongue and groove type, detachable means for detaching the tugboat from the barge by simply swinging the arms 50 and 51 upwardly (FIG. 5) so as to permit the pin 33A to slip out of the channels 35. The engines of the tugboat may then be reversed and the tugboat coupled, if desired, to another barge in the same manner as the tractor of a tractor-trailer combination. A crane or similar winch arrangement may be provided on the deck ofthe tugboat for raising and/or lowering the connecting member 21 into proper position for engagement of the detachable means 33 and 33A. It will also be understood, however, that nut 32B together with extension 323 of unit 32, or pins 31A and 318, or even pins 13A and 13B, could form the detachable means according to the present invention. Thus, the pivot pins 13A and 1313 can be made disconnectable so that substantially the entire coupling apparatus, with the exception of the mounting means 12, 12, can be mounted on and remain with the barge and the aft end of connecting member 21 can be disconnected from the tugboat at the joints 13A, 138 in order to separate the vessels.

All of the aforementioned pivot joints providing pivotal movement about the axes A, X, Y and Z are preferably arranged at such an elevation that they will, at least under normal operating conditions, remain out of the water. All of the aforesaid pivot pins are preferably received in the respective openings described above with sufficiently close fits so as to minimize the possibility of relative jerking movements between the two vessels when operating in coupled condition. It will be seen that the coupling apparatus according to the present invention permits very substantial independent pitching, rolling, yawing and heaving movements of the coupled vessels as well as combinations of the latter movements. The U-shaped compression connecting member 21, by being shaped to straddle the bow of the tug with clearance and because of the pivotal connections 13A, 13B and 33A at opposite ends thereof, can remain relatively horizontal under most conditions of operation even when the tugboat pitches substantially relatively thereto. As a result of this double-pivot action of the U-shaped connecting member 21, namely about axis A at one end and axis 2 at the opposite end and because the axis A is located substantially amidships ofthe tug, there is possible also a quite substantial heaving motion of the tugboat and the barge relative to one another.

Similarly, relatively rolling motions about axis X (FIG. 4) are also practically unlimited. Relatively unlimited yaw motion between the two vessels is accomplished with the pivot means 31A and 31B acting along the axis Y. The latter yaw movement is further enhanced by positioning of the thrust coupling means 30 ahead of the bow of the tug and a given distance aft of the barge, thus permitting the connecting member 21 sufficient freedom of movement to swing about axis Y through an angle of approximately 190 with respect to the longitudinal axis of barge 40. The size and shape of the clearance space provided intermediate the upper and lower portions 42A and 42B of the truss 42 are chosen such as to permit entry therebetween of the forward portion 21A of the connecting member 21 and to permit relative rolling movement of approximately :30 between the tugboat and the barge even when the longitudinal axes of the two vessels are at an angle of close to i (dottedline positions of FIG. 1). Relative heaving, rolling, pitching and yaw movements, or combinations thereof, between the pushing tug and the pushed barge, of such magnitudes as are forseeably encountered in open sea operations are thus possible with the apparatus according to the present invention.

It will be seen (FIGS. 2 and 3) that in the preferred embodiment of the thrust coupling means 30 both the axes Y and Z intersect the axis of roll X at longitudinally separate but closely spaced points thereof. It will further be seen that in the preferred embodiment the Z axis of the thrust coupling means is parallel to the athwartships axis A on the tugboat. The axis Y is preferably located in the vertical longitudinal median plane of the barge and is preferably substantially perpendicular to the longitudinal axis of the barge.

In operation, the compression connecting member 21 remains relatively horizontal. As the tugboat 10 and the barge 40 heave and/or pitch independently of each other the connecting member 21 pivots at opposite ends thereof, about the axes A and Z, respectively, as required to maintain the connecting member as close to the horizontal as possible. In this connection it will also be seen that the elevational change of the aft end of member 21 is minimized because the pivot axis A is located approximately amidships, and the pitching of the tugboat, of course, occurs generally about a lateral axis parallel to and in the region of the axis A, i.e., a lateral axis through the center of buoyancy of the tugboat. As a result of the relatively horizontal disposition of connecting member 21 there is always assured a substantial longitudinal force component transmitted via member 21 from the pushing vessel to the pushed vessel, thus minimizing force components in directions tending to push the stern of the barge up or down.

Each of the vessels connected by the coupling apparatus according to the present invention can therefore heave, pitch, yaw and roll freely relative to the other vessel without restraint by the coupling apparatus. For example, the coupling apparatus according to the present invention theoretically would permit the vessels to roll 360 with respect to one another, yaw :90 with respect to one another, pitch in excess of :90 with respect to one another and heave, i.e., move vertically with respect to one another, by an amount limited only by the length of the connecting member 21. Moreover, because of the rigidity of the tapered frames of connecting member 21 and of the truss member 42, such members cannot be readily deformed by forces acting thereon so that relative longitudinal movement between the vessels is effectively prevented. It is intended by the foregoing to show that as a practical matter no restraint of relative movement between the coupled vessels, other than relative longitudinal movement, is imposed by the coupling apparatus according to the present invention.

Steering the barge with the tugboat coupled thereto may be accomplished in accordance with the invention, using the securing and tensioning cables 45 and 46, on opposite sides of the tug, in well known manner, to move and/or maintain the tugboat in line or at any given angle with respect to the barge.

It is evident that the coupling mechanism can normally be the equipment of the tugboat or of the barge, or, with the type of construction shown in FIG. 5, the disengageable means 33A and 33 coupling the connecting member 21 to unit 32 can be released so that one portion of the coupling means remains connected to the barge while the remaining portion of the apparatus remains connected to the tug.

As a further embodiment of the present invention it will be readily understood that not only a barge and a tugboat can be connected in the manner described but, according to applicants novel invention, two or more barges in a train of barges can be connected with the described apparatus. Thus, if desired, a barge can be equipped with a first mounting means 12, 12' substantially amidships thereof and with a second mounting means 42 at the stern thereof. A series of such barges can then be coupled together in the form of a train ahead of a tugboat in the same manner as illustrated herein for a single barge and tugboat.

it will also be understood that since the fuel capacity of a tug is limited, an extra fuel supply can be carried on board the pushed vessel and connected with a flexible hose to the fuel tank of the tug thus making extended ocean going trips possible. Furthermore, it will be seen, in the event the pushed vessel is especially long or tall so as to interfere with the visibility from the tug, a pilot house with full power and steering controls may be provided on the pushed vessel and appropriately connected with the tug, by hydraulic or electric lines, for controlling the latter, The latter arrangement would make it possible also to couple a tug to the stern ofa large ocean going vessel such as a super tanker, using apparatus according to the present invention.

It will be obvious to those skilled in the art that various changes and modifications may be made in the embodiments presented herein without departing from the spirit and scope ofthe invention.

lclaim:

1. An apparatus for coupling together a pushing vessel and a pushed vessel and for steering the coupled pushed vessel, comprising in combination:

first support means rigidly connected to the stern portion of the pushed vessel;

second support means rigidly connected to the midship portion ofthe pushing vessel;

elongated compression connecting means comprising an elongated U-shaped connecting member having at one longitudinal end portion thereof a pair of elongated leg portions pivotably connected to said second support means for pivotal movement of said connecting means relative to said pushing vessel about an athwartships axis located generally amidships of said pushing vessel, and having at its other longitudinal end portion, a central portion connecting said leg portions forward of the bow of said pushing vessel, said central and leg portions defining between themselves a space adapted to receive the bow of the pushing vessel with sufficient clearance to permit said bow to move freely within said U-shaped member during relative pivotal movement therebetween, said U- shaped member being configurated to straddle the bow of said pushing vessel; and

universal thrust coupling means for coupling together said first support means and said other longitudinal end portion of said elongated connecting means for three degrees of freedom of movement therebetween, whereby said pushing and said pushed vessel are linked together for joint movement while being free to rise and fall, as well as pitch, roll and yaw relatively to one another.

2. The apparatus according to claim 1 wherein said first support means comprises a support structure having an upper and a lower portion extended rearwardly of the stern of said pushed vessel, said upper and lower portions of said support structure being spaced apart a distance sufficient to receive therebetween said universal thrust coupling means.

3. The apparatus according to claim 2 further comprising pivot means at the rearmost portion of said upper and lower portions of said support structure, said pivot means having an axis which is substantially in the vertical longitudinal median plane ofsaid pushed vessel.

4. The apparatus according to claim 1 wherein the length of said connecting means at least slightly exceeds one-half the longitudinal length ofsaid pusher vessel.

5. The apparatus according to claim 1 wherein said coupling means comprises a first joint member pivotably connected to said first support means for pivotal movement about a first axis of rotation, a second joint member pivotably connected to said first joint member for pivotal movement about a second axis of rotation substantially perpendicular to said first axis, and means on said second joint member for pivotably connecting thereto said other end portion of said elongated connecting means for pivotal movement ofsaid connecting means relative to said second joint member about a third axis substantially perpendicular to each ofsaid first and second axes.

6. The apparatus according to claim 5 wherein said coupling means comprises pivot means at each of said first, second and third axes, respectively, and said second support means comprises pivot means pivotally supporting said connecting means, at least one of said pivot means forming a detachable connection.

7. The apparatus according to claim 5, wherein said pivot means of said second support means comprises said detachable means for detachably coupling together said second support means and said connecting means.

8. The apparatus according to claim 1 wherein said athwartships axis is located substantially at the longitudinal center of said pushing vessel a given vertical distance above the water line, said coupling means comprising pivot means coupling said connecting means to the remainder of said coupling means for pivotal movement about a second axis substantially parallel to said athwartships axis and located above the water line of said pushed vessel a distance substantially equal to said given distance so that said elongated connecting means will be substantially horizontal when said vessels are linked together.

9. The apparatus according to claim 1, wherein said first support means comprises pivot means having a normally substantially vertical axis located aft of the longitudinal end extremity of said stern of said pushed vessel a distance which exceeds at least slightly one-half the width dimension of said pushing vessel.

10. The apparatus according to claim 5 wherein said first and third axes of rotation of said coupling means are spaced from one another, said second axis intersecting each of said spaced first and third axes at substantially right angles and said third axis being substantially parallel to said athwartships axis of said support means, said connecting means being movable with respect to said second support means only about said athwartships axis.

11. The apparatus according to claim 1, said coupling means being located substantially midway between the bow of said pushing vessel and the stern of said pushed vessel when the latter vessels are in longitudinal alignment with one another.

12. The apparatus according to claim 1 further comprising a pair of guy-lines connecting opposite sides of the stern of said pushed vessel with the corresponding opposite sides of said pushing vessel.

13. The apparatus according to claim 1 wherein said first support means comprises an upper and a lower structural member connected rigidly to the stern of the pushed vessel at a location above the water line, and each such member having a portion extending rearwardly of said stern for connection to said coupling means, said upper and lower members being spaced apart a distance sufficient to receive therebetween ofa portion of said connecting means when said vessels turn relatively to one another from a position in which their longitudinal axes are in alignment toward a position in which their longitudinal axes make right angles with one another.

14. The apparatus according to claim 13 wherein said leg portions being spaced apart a distance exceeding the width dimension of said pushing vessel and said central portion of said connecting means comprises the portion which is receivable in said space between said upper and lower members.

15. The apparatus according to claim 14 wherein said spacing between said upper and lower members is sufficiently large to permit a rolling movement of the pushing vessel of approximately plus or minus 30, from the horizontal, about its longitudinal axis irrespective of the relative angular position of said vessels.

16. The apparatus according to claim 5 wherein said first support means comprises a pair of vertically spaced portions, said first joint member extends between the end extremities of said vertically spaced portions of said first support means and comprising a pair of pivot pins connecting said first joint member to said vertically spaced portions for pivotal movement about said first axis, said first joint member having a first bore extending therethrough intermediate said pivot pins, said second joint member extending through and being received in said first bore for rotational movement therein with respect to said first joint member about said second axis which intersects said first axis at right angles and said second joint member defining a second bore therethrough whose axis is normal to said second axis and which is spaced from said first axis, pivot 10 pin means fixedly received in said second bore and having end portions outwardly from opposite ends of said second bore, said connecting means including a pair of parallel forked end portions adapted to receive therebetween a portion of said second joint member with said forked portion adapted to receive therein said outwardly extending end portions, respectively, of said pivot pin means, said connecting means further comprising a pair of arms swivably connected to said end portion, respectively, for releasably locking said pivot pinmeans to said forked end portions for pivotal movement between said second joint member and said connecting means while detachably linking said vessels together.

17. An apparatus for coupling together a pushing vessel having a tapered bow and a pushed vessel and steering the coupled pushed vessel comprising, in combination:

an elongated compression connecting member comprising a U-shaped frame straddling said bow and being tapered in the region thereof adjacent said bow for extending alongside the pushing vessel with its apex forward and means attaching the spaced ends of said U-shaped tapered frame a substantial distance aft of the bow, the cords of the frame adjacent to opposite sides of the bow of the tugboat being of dog legged shape generally complementary to the bow portion of the pushing vessel;

pivot means connecting one end of said compression connecting member to said pushing vessel for pivotal movement relative to such pushing vessel about an athwartships axis located substantially amidships of said pushing vessel;

and universal thrust coupling means connecting the other end of said compression connecting member to the stern of said pushed vessel for three degrees of freedom of movement therebetween whereby said pushed vessel and said pushing vessel are free to rise and fall as well as roll, pitch and yaw relative to one another.

18. The apparatus according to claim 17 in which said pushed vessel is a barge and said pushing vessel is a tugboat and wherein said means connecting said one end of said compression connecting member to said tugboat is attached to the sides of the tugboat amidships thereof.

19. The apparatus according to claim 18 in which said compression connecting member straddles the bow of said tugboat, said one end ofsaid compression connecting member including a pair of corresponding end portions pivotally connected to opposite sides of said tugboat substantially amidships thereof for pivotal movement of said connecting member about an athwartships axis.

20. The apparatus according to claim 17 wherein said universal thrust coupling means comprises a series of articulated pivoting units connecting said other end of said compression connecting member and the stern of said pushed vessel and providing a separate pivoting about the x, y and z axes as exemplified by a rectangular coordinate system for providing three degrees of freedom of movement to accommodate simultaneously for pitch, roll and yaw of the coupled vessels,

21. The apparatus according to claim 17 wherein said connecting member is of rigid truss construction.

22. The apparatus according to claim 17 wherein said thrust coupling means is connected to the apex of said connecting member, said legs of said U-shaped member pivotally connected to said pushing vessel for pivotal movement about an athwartship axis substantially amidships of said pushing vessel. 

1. An apparatus for coupling together a pushing vessel and a pushed vessel and for steering the coupled pushed vessel, comprising in combination: first support means rigidly connected to the stern portion of the pushed vessel; second support means rigidly connected to the midship portion of the pushing vessel; elongated compression connecting means comprising an elongated U-shaped connecting member having at one longitudinal end portion thereof a pair of elongated leg portions pivotably connected to said second support means for pivotal movement of said connecting means relative to said pushing vessel about an athwartships axis located generally amidships of said pushing vessel, and having at its other longitudinal end portion, a central portion connecting said leg portions forward of the bow of said pushing vessel, said central and leg portions defining between themselves a space adapted to receive the bow of the pushing vessel with sufficient clearance to permit said bow to move freely within said U-shaped member during relative pivotal movement therebetween, said U-shaped member being configurated to straddle the bow of said pushing vessel; and universal thrust coupling means for coupling together said first support means and said other longitudinal end portion of said elongated connecting means for three degrees of freedom of movement therebetween, whereby said pushing and said pushed vessel are linked together for joint movement while being free to rise and fall, as well as pitch, roll and yaw relatively to one another.
 2. The apparatus according to claim 1 wherein said first support means comprises a support structure having an upper and a lower portion extended rearwardly of the stern of said pushed vessel, said upper and lower portions of said support structure being spaced apart a distance sufficient to receive therebetween said universal thrust coupling means.
 3. The apparatus according to claim 2 further comprising pivot means at the rearmost portion of said upper and lower portions of said support structure, said pivot means having an axis which is substantially in the vertical longitudinal median plane of said pushed vessel.
 4. The apparatus according to claim 1 wherein the length of said connecting means at least slightly exceeds one-half the longitudinal length of said pusher vessel.
 5. The apparatus according to claim 1 wherein said coupling means comprises a first joint member pivotably connected to said first support means for pivotal movement about a first axis of rotation, a second joint member pivotably connected to said first joint member for pivotal movement about a second axis of rotation substantially perpendicular to said first axis, and means on said second joint member for pivotably connecting thereto said other end portion of said elongated connecting means for pivotal movement of said connecting means relative to said second joint member about a third axis substantially perpendicular to each of said first and second axes.
 6. The apparatus according to claim 5 wherein said coupling means comprises pivot means at each of said first, second and third axes, respectively, and said second support means comprises pivot means pivotally supporting said connecting means, at least one of said pivot means forming a detachable connection.
 7. The apparatus according to claim 5, wherein said pivot means of said second support means comprises said detachable means for detachably coupling together said second support means and said connecting means.
 8. The apparatus according to claim 1 wherein said athwartships axis is located substantially at the longitudinal center of said pUshing vessel a given vertical distance above the water line, said coupling means comprising pivot means coupling said connecting means to the remainder of said coupling means for pivotal movement about a second axis substantially parallel to said athwartships axis and located above the water line of said pushed vessel a distance substantially equal to said given distance so that said elongated connecting means will be substantially horizontal when said vessels are linked together.
 9. The apparatus according to claim 1, wherein said first support means comprises pivot means having a normally substantially vertical axis located aft of the longitudinal end extremity of said stern of said pushed vessel a distance which exceeds at least slightly one-half the width dimension of said pushing vessel.
 10. The apparatus according to claim 5 wherein said first and third axes of rotation of said coupling means are spaced from one another, said second axis intersecting each of said spaced first and third axes at substantially right angles and said third axis being substantially parallel to said athwartships axis of said support means, said connecting means being movable with respect to said second support means only about said athwartships axis.
 11. The apparatus according to claim 1, said coupling means being located substantially midway between the bow of said pushing vessel and the stern of said pushed vessel when the latter vessels are in longitudinal alignment with one another.
 12. The apparatus according to claim 1 further comprising a pair of guy-lines connecting opposite sides of the stern of said pushed vessel with the corresponding opposite sides of said pushing vessel.
 13. The apparatus according to claim 1 wherein said first support means comprises an upper and a lower structural member connected rigidly to the stern of the pushed vessel at a location above the water line, and each such member having a portion extending rearwardly of said stern for connection to said coupling means, said upper and lower members being spaced apart a distance sufficient to receive therebetween of a portion of said connecting means when said vessels turn relatively to one another from a position in which their longitudinal axes are in alignment toward a position in which their longitudinal axes make right angles with one another.
 14. The apparatus according to claim 13 wherein said leg portions being spaced apart a distance exceeding the width dimension of said pushing vessel and said central portion of said connecting means comprises the portion which is receivable in said space between said upper and lower members.
 15. The apparatus according to claim 14 wherein said spacing between said upper and lower members is sufficiently large to permit a rolling movement of the pushing vessel of approximately plus or minus 30*, from the horizontal, about its longitudinal axis irrespective of the relative angular position of said vessels.
 16. The apparatus according to claim 5 wherein said first support means comprises a pair of vertically spaced portions, said first joint member extends between the end extremities of said vertically spaced portions of said first support means and comprising a pair of pivot pins connecting said first joint member to said vertically spaced portions for pivotal movement about said first axis, said first joint member having a first bore extending therethrough intermediate said pivot pins, said second joint member extending through and being received in said first bore for rotational movement therein with respect to said first joint member about said second axis which intersects said first axis at right angles and said second joint member defining a second bore therethrough whose axis is normal to said second axis and which is spaced from said first axis, pivot pin means fixedly received in said second bore and having end portions outwardly from opposite ends of said second bore, said connecting means including a pair of parallel forked end Portions adapted to receive therebetween a portion of said second joint member with said forked portion adapted to receive therein said outwardly extending end portions, respectively, of said pivot pin means, said connecting means further comprising a pair of arms swivably connected to said end portion, respectively, for releasably locking said pivot pin means to said forked end portions for pivotal movement between said second joint member and said connecting means while detachably linking said vessels together.
 17. An apparatus for coupling together a pushing vessel having a tapered bow and a pushed vessel and steering the coupled pushed vessel comprising, in combination: an elongated compression connecting member comprising a U-shaped frame straddling said bow and being tapered in the region thereof adjacent said bow for extending alongside the pushing vessel with its apex forward and means attaching the spaced ends of said U-shaped tapered frame a substantial distance aft of the bow, the cords of the frame adjacent to opposite sides of the bow of the tugboat being of dog legged shape generally complementary to the bow portion of the pushing vessel; pivot means connecting one end of said compression connecting member to said pushing vessel for pivotal movement relative to such pushing vessel about an athwartships axis located substantially amidships of said pushing vessel; and universal thrust coupling means connecting the other end of said compression connecting member to the stern of said pushed vessel for three degrees of freedom of movement therebetween whereby said pushed vessel and said pushing vessel are free to rise and fall as well as roll, pitch and yaw relative to one another.
 18. The apparatus according to claim 17 in which said pushed vessel is a barge and said pushing vessel is a tugboat and wherein said means connecting said one end of said compression connecting member to said tugboat is attached to the sides of the tugboat amidships thereof.
 19. The apparatus according to claim 18 in which said compression connecting member straddles the bow of said tugboat, said one end of said compression connecting member including a pair of corresponding end portions pivotally connected to opposite sides of said tugboat substantially amidships thereof for pivotal movement of said connecting member about an athwartships axis.
 20. The apparatus according to claim 17 wherein said universal thrust coupling means comprises a series of articulated pivoting units connecting said other end of said compression connecting member and the stern of said pushed vessel and providing a separate pivoting about the x, y and z axes as exemplified by a rectangular coordinate system for providing three degrees of freedom of movement to accommodate simultaneously for pitch, roll and yaw of the coupled vessels.
 21. The apparatus according to claim 17 wherein said connecting member is of rigid truss construction.
 22. The apparatus according to claim 17 wherein said thrust coupling means is connected to the apex of said connecting member, said legs of said U-shaped member pivotally connected to said pushing vessel for pivotal movement about an athwartship axis substantially amidships of said pushing vessel. 